From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60718C4727F for ; Wed, 30 Sep 2020 14:36:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DE2A3206D4 for ; Wed, 30 Sep 2020 14:36:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WUizy0hK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE2A3206D4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58610 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kNdDO-0000b1-Fn for qemu-devel@archiver.kernel.org; Wed, 30 Sep 2020 10:36:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53150) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kNdAM-0005PK-Sg for qemu-devel@nongnu.org; Wed, 30 Sep 2020 10:33:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:35876) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kNdAH-0002Ic-K3 for qemu-devel@nongnu.org; Wed, 30 Sep 2020 10:33:10 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601476384; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v63GnPIUgaVaBNhYbb3kTHc8QbGwK8C0y29dLzJ6+Mo=; b=WUizy0hKAy59VdzqmigHdcq8hOgKx1CQMQGCcdR3AiW+hokh6POqrmcPDdHvyeh7wZrnCz ww+SV/yzBRcu3VHIEMpPUOCeehKybWBbRBGOD3hmyiUCgqGBCQkpODLsubi9P3jwHESEdk +yRI5gwA6yq7hWp+v0KwpTMioi7tGSI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-525-2IC2iQOPORuVaFMhfBGiSg-1; Wed, 30 Sep 2020 10:33:02 -0400 X-MC-Unique: 2IC2iQOPORuVaFMhfBGiSg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 69F308030BE; Wed, 30 Sep 2020 14:33:01 +0000 (UTC) Received: from starship (unknown [10.35.206.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2AFE160C07; Wed, 30 Sep 2020 14:32:56 +0000 (UTC) Message-ID: <0d124b6991e607e496da4afa39027320e617aa0e.camel@redhat.com> Subject: Re: [PATCH 08/10] scsi/scsi_bus: Add scsi_device_get From: Maxim Levitsky To: Paolo Bonzini , qemu-devel@nongnu.org Date: Wed, 30 Sep 2020 17:32:55 +0300 In-Reply-To: <20200925172604.2142227-9-pbonzini@redhat.com> References: <20200925172604.2142227-1-pbonzini@redhat.com> <20200925172604.2142227-9-pbonzini@redhat.com> User-Agent: Evolution 3.36.3 (3.36.3-1.fc32) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mlevitsk@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=mlevitsk@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/30 00:26:33 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.469, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stefan Hajnoczi , stefanha@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 2020-09-25 at 13:26 -0400, Paolo Bonzini wrote: > From: Maxim Levitsky > > Add scsi_device_get which finds the scsi device > and takes a reference to it. > > Suggested-by: Stefan Hajnoczi > Signed-off-by: Maxim Levitsky > Message-Id: <20200913160259.32145-8-mlevitsk@redhat.com> > Signed-off-by: Paolo Bonzini > --- > Compared to Maxim's patch, I am avoiding the extra argument > to do_scsi_device_find by moving the RCU_READ_LOCK_GUARD() > out of do_scsi_device_find itself. Which is a good idea, although my mindset was like, I got a device, lets just grab a ref to it before it disappears and then do whatever I want. The extra argument was ugly no doubt though. Best regards, Maxim Levitsky > > hw/scsi/scsi-bus.c | 11 +++++++++++ > include/hw/scsi/scsi.h | 1 + > 2 files changed, 12 insertions(+) > > diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c > index 7599113efe..eda8cb7e70 100644 > --- a/hw/scsi/scsi-bus.c > +++ b/hw/scsi/scsi-bus.c > @@ -73,6 +73,17 @@ SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun) > return do_scsi_device_find(bus, channel, id, lun, false); > } > > +SCSIDevice *scsi_device_get(SCSIBus *bus, int channel, int id, int lun) > +{ > + SCSIDevice *d; > + RCU_READ_LOCK_GUARD(); > + d = do_scsi_device_find(bus, channel, id, lun, false); > + if (d) { > + object_ref(d); > + } > + return d; > +} > + > static void scsi_device_realize(SCSIDevice *s, Error **errp) > { > SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s); > diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h > index 7a55cdbd74..09fa5c9d2a 100644 > --- a/include/hw/scsi/scsi.h > +++ b/include/hw/scsi/scsi.h > @@ -190,6 +190,7 @@ int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed); > int scsi_SG_IO_FROM_DEV(BlockBackend *blk, uint8_t *cmd, uint8_t cmd_size, > uint8_t *buf, uint8_t buf_size); > SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int target, int lun); > +SCSIDevice *scsi_device_get(SCSIBus *bus, int channel, int target, int lun); > > /* scsi-generic.c. */ > extern const SCSIReqOps scsi_generic_req_ops;